Large-capacity storage media have become popular in recent years. In ultrasonographic devices, various kinds of patient data, such as an ultrasonic diagnostic image, are stored in storage media provided within the device or externally and the stored patient data are used. FIG. 8 shows an ultrasonographic device described in Patent Document 1 as an example of data to be stored. The device includes a patient report data memory 14, a fetus/normal build data memory 15, a fetus pictogram data memory 16, and a fetus standard deviation pictogram data memory 17. In FIG. 8, reference number 1 indicates an operating unit. Reference number 2 indicates an echo image processing unit. Reference number 3 indicates a central processing unit. Reference number 8 indicates an echo measuring unit. Reference number 9 indicates an image display processing unit. Reference number 11 indicates a display unit.    Patent Document 1: Japanese Patent Application Publication No. Heisei 11-299791 (Abstract)
However, in a conventional ultrasonographic device, when the ultrasonographic device is discarded, resold, or the like, there is risk of patient data, which is personal information, stored in the storage medium being leaked. To delete the patient data stored in the storage medium when the ultrasonographic device is discarded or resold, each piece of data is required to be individually deleted. Alternatively, the storage medium itself is required to be destroyed. Therefore, a large amount of labor is required and complete deletion of the data cannot be conducted. Moreover, the method of destroying the storage medium itself is not applicable when the ultrasonographic device is resold.